The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingReassembly (2005/11-2006/01)
Install front drive shaft bearing
Using sst and a press, press in the drive shaft
bearing to the inboard joint rh.
Sst 09527-10011, 09710-04081
Notice:
The bearing should be installed completely.
Using a snap ring expander, install a new drive shaft
hole snap ring.
...
Blower motor
On-vehicle inspection
Inspect blower motor (for automatic air conditioning system)
Disconnect the blower motor connector.
Connect the positive (+) lead from the battery to
terminal 1 and negative (-) lead to terminal 2, and
then check that the motor operates smoothly.
If the ...
Registration
Perform vehicle stability control system recognition in ecm
Notice:
If the vehicle has both cruise control and vsc, when
replacing ecm, perform vsc recognition as follows:
Turn the ignition switch on.
After waiting approximately 5 seconds, turn the
cruise control main switch on.
Ke ...